Is the Bare Spot reliable for the bone loss measurement?

Shoulder Elbow. 2019 Apr;11(2):106-112. doi: 10.1177/1758573218760265. Epub 2018 Mar 4.

Abstract

Background: To evaluate the reliability of the Bare Spot (BS) as an anatomical landmark for the intra-operative definition of bone loss in anterior shoulder instability.

Methods: The distances from the BS to the anterior (BS-A), posterior (BS-P) and inferior margins of the glenoid cavity were determined both under arthroscopic visualization and by an open approach in 20 shoulders.

Results: The BS did not coincide with the centre of the glenoid cavity of the studied shoulders because the BS-P distance was greater than the BS-A distance (p < 0.05) and was located 40% closer to the anterior margin. The authors suggest a correction factor: BP-A × 1.25/BP-P = 1.

Conclusions: The BS is located at a mean distance of 40% of the joint diameter, relative to the anterior margin of the glenoid. This point may be used as a landmark, using a correction factor of its mostly anterior positioning. Arthroscopy was reliable for bone measurements of the shoulder joint.

Keywords: cadaver; human; joint instability/pathology; joint instability/surgery; shoulder joint/pathology; shoulder joint/surgery.